Gene families with stochastic exclusive gene choice underlie cell adhesion in mammalian cells

Abstract

Exclusive stochastic gene choice combines precision with diversity. This regulation enables most T-cells to express exactly one T-cell receptor isoform chosen from a large repertoire, and to react precisely against diverse antigens. Some cells express two receptor isoforms, revealing the stochastic nature of this process. A similar regulation of odorant receptors and protocadherins enable cells to recognize odors and confer individuality to cells in neuronal interaction networks, respectively. We explored whether genes in other families are expressed exclusively by analyzing single cell RNA-seq data with a simple metric. Chromosomal segments and families are more likely to express genes concurrently than exclusively, possibly due to the evolutionary and biophysical aspects of shared regulation. Nonetheless, gene families with exclusive gene choice were detected in multiple cell types, most of them are membrane proteins involved in ion transport and cell adhesion, suggesting the coordination of these two functions. Thus, stochastic exclusive expression extends beyond the prototypical families, permitting precision in gene choice to be combined with the diversity of intercellular interactions.

The life and death of RNA across temperatures

“…A typical distribution is the Poisson distribution, with a characteristic an inverse relationship between the coefficient of variation (CV) and the mean copy number (CV 2 = 1/µ). These fluctuations due to the low discrete number of molecules can be supplemented by fluctuations in epigenetic changes, gene regulation, chromosomal neighborhood, RNA synthesis and RNA degradation [89] , [90] , [91] , [92] , [93] , which can increase noise above the Poisson level. Such an increase is prominent when transitions between active and inactive states of a promoter occur rarely and active promoter initiates the transcription of multiple mRNAs in bursts, resulting in a large burst size.…”